The invention relates to the design and structure of air filtration systems for buildings and architectural structures. More specifically, the invention relates to a system of interconnected cyclone separators built into exterior wall structures of buildings.
Filtration of breathing air has become important for the comfort, health, and safety of people living inside modern buildings and domestic structures. Commercial structures such as office buildings often have HVAC (heating, ventilation, and air conditioning) systems that pull in air from outside the building, and filter it to remove harmful particulates before adding this air to the re-circulated air inside the building. These systems are expensive and use a considerable amount of energy. Most single family homes and many apartment buildings have no such air filtration system, as outside air is introduced mainly through open windows. This method of “fresh” air infusion has only a minimum of particle filtration, consisting typically of insect screens. These screens do little to block the introduction of particulates into the home. As a result the homeowner may be exposed to allergy causing dust, pollen, soot, and other harmful particulates. This contamination results in the homeowner spending many hours trying to remove (dusting, vacuuming) these particulates from inside the home. Once introduced, the smaller particulates are extremely hard to remove due to their strong attraction to surfaces. Homeowners often employ expensive filtration units placed within the home to reduce airborne particle counts, particularly if a household member has allergies, asthma, or other respiratory ailments.
While the use of modern HVAC systems could be employed in single family homes and small apartment buildings, their capital cost is prohibitive to all but the most expensive high end homes and apartments. What is needed is a more cost effective air filtration system for single family dwellings.
Cyclone separators have been employed by modern industry for many years to separate solid particulates from gasses. Typically, they require moderately′high gas velocities (or pressure drops) provided by compressors or fans. Rarely, if ever, are they employed in the filtration of air for domestic dwellings, particularly single family homes. Air filtration for domestic dwellings is typically carried out by pleated “flow through” filter systems.
Trudell, in a Masters degree thesis document submitted to the graduate faculty of Rensselaer Polytechnic Institute, published August 2012, suggests the incorporation of single cyclone separators fashioned within solid masonry wall construction blocks. These would utilize the pressure drop created by wind pressure outside the building to force contaminated air into the cyclone separator's inlet. The reverse flow cyclonic separation would create a particulate stream leaving the bottom of the cyclone and clean air leaving the exhaust at the top, which is directed into the interior of the building.
There are a number of difficulties with the approach suggested by Trudell. The entire cyclone structure must be fabricated within the body of each solid block, which requires rather precise masonry molding techniques due to the specific geometries required by the cyclone separators. This requirement increases the cost of the construction blocks, which may be prohibitive for low cost housing or for use in third world countries. Furthermore, the use of solid molded blocks limits the use of reinforcing steel (or re-bar), commonly used within masonry walls.
These and other limitations of the prior art will become apparent to those of skill in the art upon a reading of the following descriptions and a study of the several figures of the drawing.